[MANILA] Mass murder advocate Rodrigo Duterte heads into Saturday's final rallies of an extraordinary Philippine presidential campaign as the shock favourite, but with rivals still a chance to counter his profanity-laced populist tirades.
Mr Duterte, a pugnacious 71-year-old, has rocked the political establishment with cuss-filled vows to kill tens of thousands of criminals, threats to establish one-man rule if lawmakers disobey him, and promises to embrace communist rebels.
He has also caused disgust in international diplomatic circles with a joke that he wanted to rape a "beautiful" Australian missionary who was killed in a 1989 Philippine prison riot, and boasted repeatedly on the campaign trail about his Viagra-fuelled affairs.
President Benigno Aquino, whose mother led the democracy movement that ousted dictator Ferdinand Marcos a generation ago, has warned the nation is at risk of succumbing to another dictatorship.
But Mr Duterte's anti-establishment rhetoric and promises of quick fixes to deep-rooted problems have proved hypnotic for millions of Filipinos, and he heads into Monday's election with an 11-percentage-point lead over his rivals, according to the latest survey.
Senator Grace Poe, the adopted daughter of a late movie star, and establishment bedrock Mar Roxas, are tied in second place. Vice President Jejomar Binay, the early favourite, has fallen to fourth place under the weight of a barrage of corruption allegations.
While Mr Duterte, the long-time mayor of the southern city of Davao, is undeniably the favourite, he lacks the sophisticated political machinery of some of his rivals and is not guaranteed victory, according to Manila-based political analyst Earl Parreno.
Mr Roxas, a US-educated investment banker who served as interior and transport secretaries in Aquino's administration, is in the strongest position to challenge, Mr Parreno, from the Institute of Political and Electoral Reforms, told AFP.
Mr Roxas can expect a boost of about five percentage points from the machinery of the Liberal Party, which can use its money and influence to get people into voting booths, according to Mr Parreno.
"We also still have the undecided. It's going to be a very, very close fight, a neck and neck fight, between Duterte and Roxas," Mr Parreno said.
The presidential candidates will make their final pitches to voters on Saturday with rallies in Manila that are expected to attract tens of thousands of people. Politicians are not allowed to campaign on the final day before elections.
In a sign of the nervousness that Mr Duterte will win, Mr Aquino - who is limited by the constitution to a single term of six years - made an extraordinary plea on Friday night for the other candidates to unite against the frontrunner.
Under the proposed anti-Duterte alliance, one or more of the other candidates would withdraw from the race to back the person with the best chance of winning.
Mr Roxas said he was willing to discuss the proposal with Ms Poe. However Ms Poe immediately rejected any suggestion that she should withdraw, and there were no signs on Saturday of a partnership.
Mr Duterte's media team ridiculed Mr Aquino and Mr Roxas over the alliance proposal, releasing a statement saying it "reaked of the stench of defeat".
"It also further unmasks the true character of the Aquino regime - one in the face of debacle will abandon ship and run like a headless chicken," the statement said.
In a similar manner to US Republican presidential candidate Donald Trump, Mr Duterte's blistering campaign has upended conventional political wisdom, with controversies that pundits said would doom him instead only fuelling his popularity.
Mr Duterte has promised to end crime nationally within the first six months of his presidency, with the seemingly impossible task to be achieved by ordering security forces to bypass an inefficient judicial system and go on an unprecedented killing spree.
He said tens of thousands of suspected criminals would die in the crackdown.
In a speech last week to the nation's most prominent business club, Mr Duterte acknowledged his tactics could amount to mass murder but that he would pardon himself at the end of his term if he was found guilty of such crimes.
"Pardon given to Rodrigo Duterte for the crime of multiple murder, signed Rodrigo Duterte," he said, describing the document he would write for himself.
Human rights groups have warned his comments are not merely rhetoric.
They accuse him of running vigilante squads in Davao that have killed more than 1,000 suspected criminals. At times he has boasted about his involvement, and said 1,700 people were killed, but on other occasions denied any links to the vigilantes.